Zhang Xiaomei, Li Yu-Long, Kaldy James E, Suonan Zhaxi, Komatsu Teruhisa, Xu Shaochun, Xu Min, Wang Feng, Liu Peng, Liu Xujia, Yue Shidong, Zhang Yu, Lee Kun-Seop, Liu Jin-Xian, Zhou Yi
CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.
Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
Divers Distrib. 2024 Mar 1;30(3):1-18. doi: 10.1111/ddi.13803.
The seagrass is a dramatically declined endemic species in the Northwestern Pacific from the (sub)tropical to temperate areas, however, it is also an introduced species along the Pacific coast of North America from British Columbia to northern California. Understanding the population's genetic patterns can inform the conservation and management of this species.
North Pacific.
We used sequences of the nuclear rDNA internal transcribed spacer (ITS) and chloroplast K intron maturase (), and 24 microsatellite loci to survey 34 native and nonnative populations (>1000 individuals) of throughout the entire biogeographic range. We analysed the phylogeographic relationship, population genetic structure and genetic diversity of all populations and inferred possible origins and invasion pathways of the nonnative ones.
All markers revealed a surprising and significant deep divergence between northern and southern populations of in the native region separated by a well-established biogeographical boundary. A secondary contact zone was found along the coasts of South Korea and Japan. Nonnative populations were found to originate from the central Pacific coast of Japan with multiple introductions from at least two different source populations, and secondary spread was likely aided by waterfowl.
The divergence of the two distinct clades was likely due to the combined effects of historical isolation, adaptation to distinct environments and a contemporary physical barrier created by the Yangtze River, and the warm northward Kuroshio Current led to secondary contact after glacial separation. Existing exchanges among the nonnative populations indicate the potential for persistence and further expansion. This study not only helps to understand the underlying evolutionary potential of a widespread seagrass species following global climate change but also provides valuable insights for conservation and restoration.
海草是西北太平洋从（亚）热带到温带地区急剧减少的特有物种，然而，它也是从加拿大不列颠哥伦比亚省到美国加利福尼亚州北部沿北美太平洋海岸引入的物种。了解该物种的种群遗传模式可为其保护和管理提供依据。
北太平洋。
我们使用核核糖体DNA内转录间隔区（ITS）和叶绿体K内含子成熟酶序列，以及24个微卫星位点，对整个生物地理范围内的34个本地和非本地种群（>1000个个体）进行了调查。我们分析了所有种群的系统地理关系、种群遗传结构和遗传多样性，并推断了非本地种群可能的起源和入侵途径。
所有标记都显示，在原生区域，被一个既定的生物地理边界分隔的海草南北种群之间存在惊人且显著的深度分化。在韩国和日本沿海发现了一个二次接触带。发现非本地种群起源于日本太平洋中部海岸，至少有两个不同来源种群的多次引入，二次扩散可能借助了水禽。
两个不同进化枝的分化可能是由于历史隔离、对不同环境的适应以及长江形成的当代物理屏障的综合作用，而温暖的向北黑潮在冰川分离后导致了二次接触。非本地种群之间现有的交流表明了其持续存在和进一步扩张的潜力。这项研究不仅有助于了解全球气候变化后一种广泛分布的海草物种潜在的进化潜力，还为保护和恢复提供了有价值的见解。
